class_docstr: Base class for row group indexers.
docstr: index values in given rows.
docstr_tok: ["index","values","in","given","rows","."]
code: def build_index(self, decoded_rows, piece_index):
      """index values in given rows."""
  
file_path: petastorm/petastorm/etl/__init__.py
imports: import abc
  import six
label_desc: Use image node_id 6 for calling the RowGroupIndexerBase obj's underlying member method code with example usage: obj.build_index(decoded_rows, piece_index) without return types